Question

Im trying to create an indexed 2D array within Python, but I keep running into errors, one way or another.

The following code:

#Declare Constants (no real constants in Python)
PLAYER = 0
ENEMY = 1
X = 0
Y = 1
AMMO = 2
CURRENT_STATE = 3
LAST_STATE = 4

#Initilise as list
information_state = [[]]
#Create 2D list structure
information_state.append([PLAYER,ENEMY])
information_state[PLAYER].append ([0,0,0,0,0])#X,Y,AMMO,CURRENT_STATE,LAST_STATE
information_state[ENEMY].append([0,0,0,0,0])#X,Y,AMMO,CURRENT_STATE,LAST_STATE


for index, item in enumerate(information_state):
        print index, item

information_state[PLAYER][AMMO] = 5

Creates this output:

0 [[0, 0, 0, 0, 0]]
1 [0, 1, [0, 0, 0, 0, 0]]
IndexError: list assignment index out of range

Im used to using PHPs arrays, eg:

$array['player']['ammo'] = 5;

Is there anything similar in Python? I heard people recommending numpy, but i couldn’t figure it out 🙁

Im new to this Python stuff.

Note: Using Python 2.7

Answer 1

i think you should have a look at python’s data structures tutorial and what you’re looking for is called a dictionary here, which is a list of key-value pairs.

in your case, you could use a nested dictionary as a value for a key, so that you could call

## just examples for you ##

player_dict_info = {'x':0, 'y':0, 'ammo':0}
enemy_dict_info = {'x':0, 'y':0, 'ammo':0}
information_state = {'player': player_dict_info, 'enemy': enemy_dict_info}

and access every element like you did in php